US-12616338-B2 - Convection deep fat fryer heating system

Abstract

A heating system for a fluid includes a double helical coil of continuous tube, a burner, and a containment structure. The double helical coil has an inlet and an outlet disposed at a bottom end and a plurality of external radial fins spaced apart along a length thereof. The burner is centered in the double helical coil and disposed above the inlet and the outlet. The containment structure has a closed bottom end and a flue opening at an upper end. The containment structure is positioned above the inlet and the outlet to enclose the double helical coil and the draft-type burner. The burner heats the continuous tube to evenly transfer heat to the fluid while the fluid flows through the continuous tube from the inlet to the outlet.

Inventors

• Jan Claesson
• Daryl G. Erbs
• Douglas S. Jones

Assignees

• FRYMASTER LLC

Dates

Publication Date

20260505

Application Date

20210629

Claims (20)

1. 1 . A heating system for a fluid, the heating system comprising: a continuous tube having an inlet port at a first end of the tube, an outlet port at a second end of the tube, an inner coil portion and an outer coil portion, and a plurality of external radial fins spaced apart along a length thereof; and a burner in operative communication with a fuel line, wherein the burner has a longitudinal axis that is in a vertical orientation, wherein the inner coil section wraps around the burner in a vertical direction and the outer coil section wraps around the inner coil section in the vertical direction, so that the burner is centered inside the inner coil section and the inner coil section is between the outer coil section and the burner, the heating system further comprising a containment structure having a closed bottom end and a flue opening at an upper end, wherein the containment structure encloses the inner coil section, the outer coil section, and the burner, and the containment structure is positioned above the inlet port and the outlet port, wherein the burner heats the continuous tube to evenly transfer heat to the fluid while the fluid flows through the continuous tube from the inlet port to the outlet port.
2. 2 . The heating system of claim 1 , wherein the containment structure is cylindrical and abuts the outer coil section.
3. 3 . The heating system of claim 1 , wherein the burner is a radial burner.
4. 4 . The heating system of claim 1 , wherein the continuous tube is jointless between the inlet port and the outlet port.
5. 5 . The heating system of claim 1 , wherein the continuous tube has a fin density of 8 fins per inch to 15 fins per inch.
6. 6 . The heating system of claim 1 , wherein the fins are spaced along the length of the continuous tube.
7. 7 . The heating system of claim 1 , wherein the inner coil section and the outer coil section are formed from at least 3 revolutions of the continuous tube.
8. 8 . The heating system of claim 1 , wherein the inner coil section and the outer coil section are formed from at least 4 revolutions of the continuous tube.
9. 9 . The heating system of claim 1 , wherein the inlet port is in fluid level communication with a first valve communicating with a first drain pipe and wherein the outlet port is in fluid level communication with a second valve communicating with a second drain pipe, so that the continuous tube can be drained when both the first valve and the second valve are open.
10. 10 . The heating system of claim 1 , wherein the burner is a forced-draft type burner.
11. 11 . The heating system of claim 1 , wherein the inner coil section wraps around the burner in an upward vertical direction and the outer coil section wraps around the inner coil section in a downward vertical direction.
12. 12 . A convection oil fryer, the fryer comprising: a vat for cooking oil, the vat having a first end and a second end opposite the first end; a continuous tube having an inlet port at a first end of the tube, an outlet port at a second end of the tube, an inner coil portion and an outer coil portion, and a plurality of external radial fins spaced apart along a length thereof; and a burner in operative communication with a fuel line, wherein the burner has a longitudinal axis that is in a vertical orientation, wherein the inner coil section wraps around the burner in a vertical direction and the outer coil section wraps around the inner coil section in the vertical direction, so that the burner is centered inside the inner coil section and the inner coil section is between the outer coil section and the burner, the heating system further comprising a containment structure having a closed bottom end and a flue opening at an upper end, wherein the containment structure encloses the inner coil section, the outer coil section, and the burner, wherein the containment structure is positioned above the inlet port and the outlet port; and a pump circulating cooking oil from the first end of the vat to the inlet port of the continuous tube and from the outlet of the continuous tube to the second end of the vat in a continuous loop, wherein the burner heats the continuous tube to evenly transfer heat to the cooking oil while the cooking oil flows through the continuous tube from the inlet port to the outlet port so that heated cooking oil circulates back.
13. 13 . The convection oil fryer of claim 12 , wherein the containment structure is cylindrical and is proximate the outer coil section.
14. 14 . The convection oil fryer of claim 12 , wherein the burner is a radial burner.
15. 15 . The convection oil fryer of claim 12 , wherein the continuous tube is jointless between the inlet port and the outlet port.
16. 16 . The convection oil fryer of claim 12 , wherein the continuous tube has a fin density of 8 fins per inch to 15 fins per inch.
17. 17 . The convection oil fryer of claim 12 , wherein the fins are spaced along the length of the continuous tube.
18. 18 . The convection oil fryer of claim 12 , wherein the inner coil section and the outer coil section are formed from at least 3 revolutions of the continuous tube.
19. 19 . The convection oil fryer of claim 12 , wherein the inner coil section and the outer coil section are formed from at least 4 revolutions of the continuous tube.
20. 20 . The convection oil fryer of claim 12 , wherein the inlet port is in fluid level communication with a first valve communicating with a first drain pipe and the outlet port is in fluid level communication with a second valve communicating with a second drain pipe, so that the continuous tube can be drained when both the first valve and the second valve are open.

Description

CROSS REFERENCE TO RELATED APPLICATIONS This application is a continuation in part of U.S. patent application Ser. No. 17/235,440 titled Convection Deep Fat Fryer, filed Apr. 2, 2021, which is incorporated by reference herein in its entirety. BACKGROUND OF THE DISCLOSURE 1. Field of the Disclosure The present disclosure is directed to deep fat fryers. Particularly, the present disclosure relates to a convection type deep fat fryer using cooking oil that is heated by a heating system external to the cooking oil vat. More particularly, the present disclosure relates to such a heating system that circulates oil from the cooking oil vat, through a heat exchanger external to the cooking oil vat, and back to the cooking oil vat, in a continuous loop. 2. Description of Related Art Convection fryers are desirable over standard, static type deep fat fryers for many reasons. Convection fryers can apply a much higher heat flux in a smaller footprint than is possible with a fryer that heats the cooking oil using the surfaces of the fry vat or cooking oil vat in contact with the cooking oil. This allows the convection fryer to have a smaller footprint for a given cooking capacity. The higher heating power and the movement of the oil through the food being cooked enables the convection fryer to cook larger loads with less temperature drop at the beginning of a cooking cycle and recover or adjust to a new temperature, faster than a standard fryer with less heating power. The high heating power also allows faster recovery from a setback temperature to a cooking temperature, making it more likely the operator will set back the oil temperature, thereby saving energy and increasing oil life. Many attempts have been made to design a reliable and efficient convection frying cooking system. Among other drawbacks, these prior attempts have had problems with various parts, resulting in low reliability or failures. For example, some prior convection fryers placed the heat exchange surface inside the cooking vat. When the heat exchanger is in the cooking vat, the exchanger takes up additional space increasing vat volume. The shape of the exchanger also makes the vat difficult to clean. Other prior convection fryers placed the heat exchange surface external the cooking oil vat and used atmospheric burners. These systems have experienced poor reliability due to uneven heat flux over the heat exchanger surfaces leading to hot spots which cause oil degradation. Other failures have occurred due to multiple joints in the tubing sections within the heat exchanger being exposed to the burner combustion gas. Other failures have occurred due to the oil circulation path having areas that allowed or facilitated accumulation of particles and cooking oil deposits. Accumulation over time leads to flow blockage and heat exchange failure. Heating systems of prior convection fryers use a large amount of the cabinet space under the cooking vat making it difficult or impossible for other systems to be integrated into the fryer, for example a filter system or automated top-off reservoir. Accordingly, it has been determined by the present disclosure that there is a continuing need for a convection fryer that overcomes, alleviates, and/or mitigates one or more of the aforementioned and other deleterious effects of prior devices. SUMMARY OF THE DISCLOSURE The present disclosure provides convection type deep fat fryer and a heating system that circulates oil from the cooking oil vat, through a heat exchanger external to the cooking oil vat, and back to the cooking oil vat, in a continuous loop. A heating system for a fluid includes a double helical coil of continuous tube, a burner or forced-draft type burner, and a containment structure. The double helical coil has an inlet and an outlet disposed at a bottom end and a plurality of external radial fins spaced apart along a length thereof. The burner or forced-draft type burner is centered in the double helical coil and disposed above the inlet and the outlet. The containment structure has a closed bottom end and a flue opening at an upper end. The containment structure is positioned above the inlet and the outlet to enclose the double helical coil and the burner or forced-draft burner. The burner or forced-draft burner heats the continuous tube to evenly transfer heat to the fluid while the fluid flows through the continuous tube from the inlet to the outlet. The present disclosure further provides a convection type deep fat fryer having such a heating system. The above and other objects, features, and advantages of the present disclosure will be apparent and understood by those skilled in the art from the following detailed description, drawings, and accompanying claims. As shown throughout the drawings, like reference numerals designate like or corresponding parts. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a front perspective view of a single vat convection deep fat fryer according to the present disclo